Lord of the Mysteries - Chapter 1406 - In Modern Day 4

As long as the land is square, Yan Bicheng should divide the world into four parts.
The dark organization “Ruyimen” has abducted children for many years, trained them as assassin agents, and sent them to the families of various countries for use in order to collect a lot of secrets, and gradually extended their evil hands to the court.
Feng Xiaoya, the favored minister of the King of Yan, suffers from bone melting disease. She is unparalleled in her “sickness and beauty”. For some reason, she abandons the eleventh wife, Qiu Jiang, and puts her under house arrest in the mountains. Qiu Jiang, who has forgotten his past, fled alone on a stormy night. After several twists and turns, on the way back, he met Yi Fei, the third prince of Cheng who was in trouble in a foreign land.
One wants to regain memory, the other wants to regain the throne. The two people who are incompatible with each other walk side by side towards Cheng in a bloody storm… but they find that the Ruyi Gate, which has been entrenched in Chengjing for a hundred years like a poisonous snake, seems to have undergone an unknown shock… …
The situation of the Four Kingdoms is back, and there is only one goal – to eradicate the evil organization Ruyimen!
However, as Qiu Jiang’s memory slowly recovered, a unparalleled secret finally surfaced…
Mrs. Ruyi, who is it? There is another mystery behind Ji Ying’s death?
What is the purpose of this return journey after a narrow escape, and where does it go?

- Description from novelbuddy

Su Xiao is a cold-blooded young adult who’s seeking vengeance for the death of his family, yet things ended up badly for him.

As he was taking his last breaths, he heard a voice calling him from dimensions, it was a strange system reaching him, asking him if he wanted to be saved, to be Reincarnated.

He just needed to accept a contract, Su Xiao didn’t have any choice but to do so, but he didn’t know what he signed up for!!

Travelling through worlds, doing extremely dangerous missions, collecting special items, levelling up, and even killing Protagonists…

But Su Xiao wasn’t any ordinary Contractor, Su Xiao was a Hunter!

The MC crosses over to: One Piece, Tokyo Ghoul, Naruto, Fullmetal Alchemist, Attack on Titans… and Author’s Original Worlds…

I finally managed to kill the demon lord.